1. Field of the Invention
The present invention generally relates to control systems and connecting devices and, more particularly, is directed to a control system and a connecting device suitable for interlocking a plurality of video devices such as a video tape recorder (VTR) with a satellite broadcast receiving tuner.
2. Description of the Related Art
Some electronic devices such as a VTR and a television receiver have been constructed so as to be remotely controlled in accordance with an infrared ray signal outputted from a remote control device or remote commander. In this case, normally one remote control device is provided for each electronic device. Thus, when using a plurality of such remotely-controllable electronic devices simultaneously, these electronic devices are required to be controlled respectively by corresponding remote control devices which are provided separately for the electronic devices. For example, in a case of recording a broadcasting signal received by a satellite broadcast receiving tuner on a video tape of a VTR by using remote control devices, it is required to set a receiving channel of the tuner by a remote control device for the tuner and further to start a recording operation of the VTR by a remote control device for the VTR.
However, since it is troublesome and awkward to simultaneously operate a plurality of such remote control devices, there has been proposed a technique that a plurality of electronic devices are connected through a control signal transmission line, then an infrared ray signal is transmitted from a remote control device and received by an electronic device serving as a main device, and then remaining electronic devices are operated synchronously in accordance with the received infrared ray signal.
However, in order to connect a plurality of electronic devices through the control signal transmission line, each electronic device is required to have an output and/or an input terminal for a control signal, and so this technique could not be applied to electronic devices which can not input or output the control signal. Further, even if the electronic device can input and output the control signal, only the electronic devices, which operate by the same control signal, can be connected with one another. This is because, normally, codes or formats of the control signal differ for electronic devices which are made by different manufacturers. For example, a VTR employs, as an infrared ray signal having the same function such as the start of replay, a control signal having data structure which is quite different for every manufacturer. Accordingly, even if electronic devices of different manufacturers are connected with each other, the other electronic device can not be operated by a control signal sent from a main electronic device. Thus, normally, the interlocking operation of devices connected through a control signal transmission line based on the above-described technique has been performed only among electronic devices of the same manufacturer.